


Wicked Tail

by CocoaChoux



Category: Shingeki no Kyojin | Attack on Titan
Genre: Alternate Universe - Fantasy, Anal Fingering, Anal Sex, Demon Levi (Shingeki no Kyojin), Harpy Eren Yeager, M/M, Mating, Tail Play, terms of endearment
Language: English
Status: Completed
Published: 2016-06-04
Updated: 2016-06-04
Packaged: 2018-07-12 07:04:37
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,535
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7090741
Author URL: https://archiveofourown.org/users/CocoaChoux/pseuds/CocoaChoux
Summary: <blockquote class="userstuff">
              <p>A certain demon returns to his harpy.</p>
            </blockquote>





	Wicked Tail

**Author's Note:**

  * For [MahoShoujoEren](https://archiveofourown.org/users/MahoShoujoEren/gifts).



> This is 1000% Magic's fault. 
> 
> This is a sequel to [Ruffled Feathers](http://archiveofourown.org/works/6189679), which was SUPPOSED to be a one-shot for her birthday, but Magic retaliated with [this scene from Ruffled Feathers](http://magickitt.tumblr.com/post/140728130728/you-kill-me-cocoachoux-really-ruffled-feathers) AND THEN SHE COMES BACK WITH [THIS](http://magickitt.tumblr.com/post/144435678428/cocoachouxs-fic-au-again).
> 
> Of course I have to do something to get her back but she then killed me with this [hella nsfw art here](http://mahokyojin.tumblr.com/post/144587332707/sinning-%CA%96) and I knew I was done for.
> 
> Such a bad honeybun you are, Magic. ò_ó
> 
> ...
> 
> I love it. ♥

The familiar bright light above the clouds temporarily blinded Levi as he officially entered the cloud realm. The demon clenched his eyes shut from the natural sunlight that dared to burn his retinas, trying to maintain his stance on the fluffy grounds.

“I’m never going to get used to the damn fire orb, am I?” he muttered to himself before slowly adjusting to the open land before him.

Standing straighter now that he regained balance, he walked across the cloudy surface towards the oh-so-familiar blue and purple forest. He breathed in the fresh and clean air as he walked passed the trees, his tail whipping behind him with each step he took.

He heard faint chirping from a distance and noted that the forest was relatively silent, assuming that any nearby creatures scurried away from his presence; however, a quiet squeak made him halt to a stop, his pointed ears twitched to try to find where the sound came from. A soft murmur from below made him look down to see a teal-colored mushroom creature looking up at him with fear.

Oh, he almost stepped on the poor thing.

He quietly knelt down and patted the top of the creature with his index finger and it jumped from the contact and ran away towards the trees. Levi followed it with his eyes and he raised a brow when the mushroom turned into a tree, trying to disguise itself, but doing a poor job since it was still teal compared to the blues and purples of the forest. He let out a humorous chuckle before standing up and started walking down the path again.

The sound of rushing water soothed his body like a relaxing balm, and his legs moved faster on their own accord. He gripped the satchel bag he was carrying (something he picked up from the natural realm a long time ago) as the forest ended and he reached the clearing where Crystal Falls was in view. He looked around and up at the sky but saw no Eren. Levi’s lips tugged down as he reached the edge of the water, sitting on the rock that he helped Eren with his feathers the first time he met the harpy.

“Where are you, my little bird?” he said more to himself, looking up at the endless skies, waiting for the blue-green feathers he loved so much to appear.

A moment or two had passed and still no Eren in sight. Starting to get hot under his clothes, Levi removed it all, careful with the bag and placed it further away from the water. He dipped into the pool with a content sigh, and wadded through the pool until he was directly under the rushing water, letting all his stress wash away. The past few weeks had a sudden influx of humans he was put in charged with and he just had about enough of screaming and crying echoing through the underground. It took a while until he managed to convince Erwin to give him the day off, and the King of Demons sent him off with a smirk just before he crossed into the natural realm and to send Eren his regards. Asshole.

Levi’s thoughts were interrupted when his ears twitched at the sound of muffled flapping. He swam out from his spot and he spotted the shadow of a figure headed his way. The closer the mysterious figure got, the more he smiled. The smile turned into a grin when he saw beautiful tan skin and blue-green feathers of his harpy.

“Levi!” Eren exclaimed as he flew closer. Levi wasn’t able to say anything before he was taken out of the water, holding onto Eren’s torso as the brunet twirled them both up into the sky and diving down to the pool, dropping Levi into the water with a shrilled laugh when the demon made a large splash.

Air bubbles popped up from where Levi landed before ebony hair emerged. “Eren,” Levi seethed out the moment he broke through the surface. His glare didn’t have the intended effect as he watched the harpy laughing on the rocks where he landed on. Levi muttered something under his breath as he slowly swam to where Eren was.

“Apologies for being late,” was the first thing Eren said the moment he was close, “I had to deliver something for my father and had to fly to the opposite end of the kingdom.”

“No fairies or pixies this time?” Levi asked with a lazy grin.

Eren huffed. “I had to deliver this herbal salve to a dragon for their newborn. Almost got set on fire when they caught sight of me.”

“Pity, I would have loved to have an excuse to touch your feathers.”

Eren smiled bashfully before he knelt on the stone and folded his wings on his laps, close to Levi. “You know you’re more than welcome to. You have my full permission to touch as you please.”

The demon hummed as he stroked the feathers, reveling on how soft they were. Eren must have been taking extra care of them, Levi noted. No glitter or sparkles in sight. He leaned forward and rested his head on the blue-green plumes, loving the gentle caress on his skin. He gently kissed one of the feathers before staring at Eren’s brilliant green eyes. “I’ve missed you, Eren.”

“And I have missed you, Levi,” Eren said softly. The harpy folded the unoccupied wing over Levi’s laxed form, smiling when Levi subconsciously moved closer to press against his feathers. His demon could be quite uncharacteristically adorable at times and Eren was glad he was able to see this side of the silver-eyed being. “I feel a void when you’re not with me and I constantly yearn for our next meeting so I may hold you like this again,” he said.

Levi sighed at the silky touch of the feathers. “I feel the same as you, my little dove. Not having your presence around makes me more irritable than usual and I always crave for your affection at all times of the day and night.”

Eren hummed deeply from his chest in content from the demon’s words. “You make me happy, Levi.” The harpy slightly turning Levi’s head so he could see the left ear, pierced with the feather he gave to him about a year ago. “I’m glad that you still have this.”

“Of course,” Levi said as he tilted his head to show Eren the piercing more clearly. “Though, Hange had a field day when they saw that I came back with it to show my dedication to you. They would not stop pestering me about it.” The harpy chuckled and Levi closed his eyes at the melodious sound.

“Hange sure was an interesting demon based on our last meeting,” Eren mentioned, remembering the time Levi showed him around the underground and introducing his fellow demon friend to him. “How are they doing?”

“Experimenting on repurposed souls and trying new torturing devices on the humans they’re in charge with. Nothing new,” Levi replied. A beat later and he said, “I also got you more ingredients for you to traverse through the natural realm and underground. I even brought enough for your sister since I know you would love to show her around in the natural realm.”

“Really? Isabel would be ecstatic!” Despite their odd position, Eren leaned forward to place a kiss on the crown of Levi’s head. “Thank you, Levi.”

“Anything for you, Eren.” Feeling his legs getting stiff from waddling under the water, he reluctantly pulled himself away and swam backwards. “Will you join me in the water?”

“Sure, but I require assistance taking off my robe.”

“With pleasure.” Levi swam back to where Eren was and lifted up so that he was sitting right next to him on the stone. Levi unbuckled the shoulder pieces and the sheer pink robe draped down to Eren’s hips. The brunet stood up and carefully stepped away from the fabric, careful as to not accidentally rip it with the talons of his feet. Before Levi could get a good look of Eren’s naked form, the harpy covered himself with his wings and jumped into the water, splashing Levi in the process.

The demon glowered at being drenched in water (for the second time) and dove in after the harpy. He opened his eyes underwater and immediately saw Eren swimming away. The wings wrapped around his body and it looked like as though Eren had a tail with the feathers acting like scales. Levi swam as close as he could under Eren and smiled when he received a grin in return, deep green eyes filled with mirth.

The two eventually went up for air and Eren laughed when Levi picked him up and twirled them around. “Levi, love, you need to bring me down. I’m getting dizzy.”

“What do you mean you’re getting dizzy? You fly around in loops all the time.” Regardless, Levi stopped but didn’t put Eren down, holding his harpy close to him. They somehow managed to make it to the edge of the pool, the water only reaching up to Levi’s knees as he continued carrying Eren in his arms.

His breath got caught in his throat at the sight of Eren, glistening under the sun rays. Droplets of water trailed down the supple body and the plumes moved along with the slight breeze. Light pink dusted across Eren’s nose and cheek and eyes glimmered as he stared at them. “Stunning,” he breathed out.

Eren looked away, shy from the sudden compliment, and the feathers on the side of his face puffed out. Ah, he was embarrassed. It was a little quirk that Levi noticed during their time together. Levi readjusted his grip so that one arm held onto Eren’s waist and the other supporting the back as Eren shook his head to dry off his feathers.

“Eren,” he whispered. There was a warmth that spread from the pit of his stomach as he held Eren against his body, desire hung between them like a thick cloud.

The harpy turned to look at him, noses touching. Levi watched as Eren’s eyes drooped and he licked his lips at the sensuous gaze the harpy was giving him. “I want to claim you.”

Eren’s eyes widened and pink cheeks turned red and feathers clung around Levi’s back. “You mean now? Here?”

Levi peppered Eren’s jaw with little kisses. “If you’re ready that is.”

“Such a patient demon you are. I’m being spoiled, aren’t I?” Eren hummed. “But I want you too. I’ve wanted you since the first day we met.”

Levi growled lowly, nipping Eren’s chin, his tail thrashing under the water. “Please tell me at any time if you wish to stop. I may be a demon, but I’m not heartless.”

“I know.” The kiss on the corner of his lips was careful. “I trust you, Levi.” Despite not being properly kissed, Eren shuddered, aroused by seeing Levi’s normally silver eyes turn into slits.

“Well then…” Levi’s look turned predatory. “Thank you for this offering,” was the last thing he said before he latched onto the juncture between Eren’s shoulder and neck, making Eren move his head to the side and moaning to give Levi more access.

His tail emerged from the water and snaked in between their bodies. Levi felt Eren’s body jolt at the touch of his tail wrapping around his length before it was pressed against Levi’s hardening member and worked them together. He smirked when Eren let out high pitched moans as his tail moved up and down the same time he kissed up along the column of Eren’s neck, nipping every so often. He paid attention to every sound Eren made and noted which areas that were more sensitive. The flat end of his tail trailed down to Eren’s balls and massaged them, making the harpy squirm from his hold. Levi was never more grateful until now that he had a tail to torture Eren with since the brunet was proving himself to be a literal handful. The demon moved his hips to slowly thrust against Eren, littering the tanned collar bone with more kisses.

“Levi!” Eren gasped as the demon continued his ministrations. His feathers twitched at every pleasurable sensation Levi has to offer and he whimpered when the tail wrapped around his balls and gave them a light squeeze. Eren bent down to try to capture Levi’s lips for a kiss, but whined when he was denied, craving for those lips that would give him instant bliss.

“Not yet,” Levi said, smirking when Eren pouted. He leaned close and whispered, “I want to wait until I enter you, Eren. I want your mind and body to be filled with just me alone. Allow me to give you the most pleasure all at once.” Without warning, he lightly slapped Eren’s ass, chuckling at the squawk the harpy let out.

Eren puffed his chest out in indignation but blinked when three fingers were presented to him. He looked at Levi with confusion.

Levi bit the inside of his cheek, trying to hold off another smirk. “Horns, remember?”

Horns? What about th- _oh_.

Eren made a noise that was a combination of a squeak and a cry, face turning redder than ever. He quickly eyed the curved horns as he took the digits in his mouth. They were quite impressive and Eren pointedly made sure his eyes didn’t look further down. He didn’t need to confirm the size as he has seen the demon naked plenty of times before.

While Eren was lost in his thoughts, Levi was trying his best to calm himself down from letting his instincts take over. He wanted to claim Eren right then and now but he would never wish for Eren to be in any pain. He bit his lips, trying to distract himself from the feeling of Eren’s tongue slipping in between his fingers, making sure to give each of them his full attention. Damn his pretty little bird for being so seductive without trying.

Deeming the fingers properly coated, Levi pulled his fingers free. There was a thin trail of saliva before it broke, Eren licking his lips as he looked at Levi expectantly. Wasting no more time, he hoisted Eren a little more up with one arm, his fingers grazing down the harpy’s spine, in between the plump round cheeks, and circling the twitching hole.

“Eren.”

“Hm?” The brunet slowly blinked from his name being called.

“Do you still want to be claimed by me?”

Eren smiled and wiggled his hips. “More than anything.”

Levi’s lips quirked up. “Let me know if anything’s uncomfortable or if you’re in pain, alright?”

“Of course, love.” A quick kiss in between the furrowed brows that were forming. “I know I’m safe in your hands.”

Levi nodded and slowly slipped a finger inside, watching Eren’s face for any signs of discomfort. He almost let out a bark of laughter when there was a look of confusion on Eren’s face as he wiggled his finger around, trying to stretch it out as much as he could. “Is everything alright down there?”

“Feels funny,” Eren admitted. His breath hitched when the finger moved more forcibly inside and released controlled, even breaths.

Levi nuzzled the side of Eren’s face and kissed the feathers there as a reward. His tail wrapped around Eren’s softening cock as a distraction before slipping in another finger. Eren’s body tightened from the additional intrusion and Levi whispered little compliments such as, “You’re doing very well, Eren,” or, “Good little bird, you’re so perfect for me,” that he knew would make Eren melt.

Levi knew he found spot when Eren froze in his arms, threw his head back, and let out a drawled-out moan. The feathers twitched in pleasure, almost tickling him, as he continued to assault the spot in faster motions.

“Ngh! Levi! P-please, more,” Eren begged, drool beginning to trickle down the side of his lips.

“Just one more, my little dove,” the demon reassured as he pushed in the final finger in. He was worried for a moment when Eren whimpered, but the thought quickly flew away when Eren started moving up and down, urging Levi to go faster. _“Fuck.”_ Whether his harpy realized it or not, his self-restraint was wearing down from all the wanton moans and debauched looks Eren was giving him.

He pulled his fingers out and before Eren could question it, he positioned himself so that he was rubbing in between Eren’s ass cheeks. He groaned when Eren purposely grinded down on him, encouraging him to go in, but he won’t, not yet. He has yet to say something very important since their reunion. “Eren.”

“Hm?” was the response he received. He stared into bright green and despite his heart pounding wildly in his chest, he felt calm when Eren looked at him with adoration. “My little robin,” he smiled when Eren huffed and snorted at the same time. He knew Eren secretly liked all the bird-related terms of endearment, and did his best to create new ones every time. Levi leaned close so that their foreheads were touching and said, “I love you. You are my skies and my wings; and I am grateful that you’ve chosen me as a mate, to love and protect you because I can’t imagine anything else I would rather dedicate myself to.”

Brilliant eyes watered and a small smile filled with love illuminated Eren’s face. “And I love you as well, Levi. You are my dreams and my strength. I will gladly give you my all: my heart, my body, my soul, my everything, for they will always belong to you, my mate.”

Levi gently smiled and finally captured Eren’s lips into a kiss and pushed inside at the same time. He groaned into Eren’s mouth from the delicious warmth that surrounded him, and slowly pushed until he was completely inside. He felt Eren tighten around his length, but he stayed still, waiting for his mate to give him the okay to move again.

Eren, on the other hand, was thrumming. The sensation of being filled was more pleasurable than he initially expected, and the way that Levi worked his tongue with his was almost overwhelming before pulling away. His mind started to get hazy and it was like all his senses were heightened. It was as though his body became sensitive and every touch Levi would give him would make him weak, yet he would still craved for more. His surroundings were muffled, but he could still hear every breath Levi took and his heart beating. It was as if they entered a world with just them in it. And all he could see in front of him, was Levi looking at him with blatant lust. Eren shuddered under the gaze and canted his hips ever so slightly, hearing the low hiss coming from Levi.

His demon was awfully patient, wasn’t he? And such patience deserved a reward.

Levi’s slitted grey eyes widened when Eren started singing. The sound was foreign, surreal even. Eren never once mentioned that he was able to sing and Levi was caught mesmerized by the strange melody that took a hold on him. His body moved on its own, and it wasn’t because of his primal desires urging him to do so; it was like as though he was caught under a spell and following its commands. He thrusted in and out slowly, spurred on by the hypnotic music, panting harshly when Eren’s voice dropped and the sound resembled a hymn.

The harpy continued singing, making Levi move faster and harder in him, delighted that he was having this kind of effect on the demon, but his voice faltered when Levi hit that one spot that made him blind with pleasure for a split second.

That second was enough time for Levi to stop his movements and let go of one of his hands to grab Eren’s chin. “Where did you learn that?” he hissed.

“From one of the sirens we’ve met when we visited the ocean in the natural realm months ago,” Eren gasped, moving his hips so that Levi would continue but the demon’s hold was strong.

“You need to learn how to use magic first in order to learn a siren’s song. So where did you-”

“Remember that vampire we stayed with during that storm?” Eren interrupted, “She had some interesting tomes to read and taught me a few things while you were talking with Erwin through the orb about extending your vacation time.” Abandoning his old tactic, Eren blinked playfully and jutted his lips to form a pout. “Can we talk about this later? I really want you to move your thick cock already and to make a mess of me.”

“Where did you learn such language?” Levi asked, giving his harpy a scandalous look.

“The vampire also introduced me to some… reference material,” he answered, humming when Levi’s hands were placed on his hips. Eren grinded down and arched his back, moaning, giving Levi a sinful show as the harpy repeated the motion to recreate the same pleasurable sensation.

Levi growled. “I should keep a better eye on you for next time we travel. Who knows what naughty things will fill your head.” He gripped onto Eren’s hips and lifted him up, giving his mate a second to wonder what was going on, before pushing the harpy down and precisely on the spot that would make the brunet see stars.

“Ah!” Eren clenched his eyes shut as Levi picked him up and slamming down again, harder this time. “O-oh, ah, Levi, ngh…” Now he was held still as Levi thrusted in and out of him, moving much faster that only a demon could accomplish.

Eren was reduced down to whimpers and moans that Levi found intoxicating. He couldn’t get enough of the delicious pleas spewing from Eren’s lips. “What beautiful sounds you make, Eren,” he whispered with a particular harsh thrust, smirking at Eren’s little whine. “It’s like music to my ears.”

“O-only, ah, for you-oh!” Eren was drooling. It was becoming a struggle to keep his eyes open.

“A song dedicated to me? I’m touched.” He was close. He could already feel the tight sensation in his groin, but he didn’t want to come just yet. His tail worked Eren’s cock in tandem with his thrusts and he slipped his tongue once more into Eren’s open mouth. The effects of his saliva worked in an instant and Eren mewled as he kissed him back roughly.

It was a few more thrusts until Eren moaned out his mate’s name as he released between their bodies, Levi’s tail jerking him to completion. He crashed forward onto Levi’s solid body, tired and spent. His wings wrapped around Levi’s shoulders as the demon continued to thrust into him, gasping, still feeling sensitive from his orgasm. He kissed everywhere he could reach and hummed deeply from his chest, almost like a purr, when he felt Levi spill inside him.

Levi panted for a few moments, leisurely kissing Eren as his heart calmed down. Eren was still making cute, delicious noises that he couldn’t get enough of when he pulled out. He could sense that Eren was about to whine from the loss, but his tail carded between Eren’s round cheeks to spread them apart, letting the fluid stream down his lover’s thighs in pearly trails. His eyes grew dark with possessiveness, listening to Eren’s gasps by his ear and watching his proof of claim marking his harpy, holding Eren even closer to him.

Once they both regained their breaths, he gingerly let Eren down back onto the cloudy surface under the water. (It was a wonder that Eren’s talons didn’t scratch him at all during their mating session, but he wasn’t going to complain.) He offered his hand and Eren accepted it with his wing, beautifully smiling at him with pink still tinged across his face.

Levi washed them both up under the waterfall, filing away the fact that Eren seemed to like his tail touching him in certain areas while they were cleaning for another time, and they made it to the bouncy grounds out of the water near their discarded clothing. He had a questioning look when Eren arranged their clothes into an odd, but strategically-placed pile, but shrugged when Eren beamed at him for approval. He slipped in between Eren’s thighs and open wings, wrapping his arms around Eren’s torso and sighed in content when the feathers wrapped around him like a protective blanket. He felt warm with content and lowered his lids shut, letting himself lie on top of Eren as the brunet laid on the ground.

“Hey, Levi?” Eren whispered.

“Hm?” He didn’t open his eyes, enjoying the feeling of Eren’s feathers brushing across his clan’s insignia branded on his back.

“Is this okay?” he asked. “Are you comfortable? Is it too warm for you? Should I go forage some nice leaves for you to relax on?”

Levi snorted, opening one of his silver eyes with amusement. “It sounds like you’re a mother hen. Don’t tell me that you’re nesting already.”

The puffing of the chest was what he expected, but he still laughed when feathers ruffled against him wildly and Eren huffed in indignation. He petted the bristling feathers and shushed Eren with soft kisses everywhere on his harpy’s chest as an apology. Even his tail was grooming the feathers to calm his mate down.

Eren cooed at the loving treatment and nuzzled closer to Levi, careful with not poking his eye with the demon’s horns. The courting feather that dangled from Levi’s pointed ear danced with the slight breeze, making Eren grin. “Fine, you win,” he reluctantly said. “Besides, if I were to start nesting, you better take responsibility for our child.”

“Can male harpies even produce children? Especially if the other partner is a demon?” Levi wondered out loud.

“I’m not too sure, but I can go digging through my dad’s library and see what I can find.”

“Sounds good to me.” Levi yawned. “Let’s rest for now.”

“Are you saying that the strongest and most feared demon of the underground is already tired after one round?” Eren teased.

Levi snapped his eyes opened and glared at his mate. “It is more for your benefit than it is for mine, little sparrow. I can assure you that I have more than enough energy to make you break right now if I so please.” His tail curled around Eren’s soft length and he inwardly grinned when the harpy squawked at his threat.

“You are so not fair,” Eren complained. Even so, he cracked a smile when his demon chuckled. He followed Levi’s example and closed his eyes, listening to the rushing waters and the faint chirping from the forest.

Just before he fell asleep, he felt Levi’s tail wrap around waist, almost carefully, and hummed in bliss. His feathers twitched in response and he didn’t even need to open his eyes to see that Levi was smiling as well.

**Author's Note:**

> I wrote this while I was sick post-convention. That's my only excuse. o3o


End file.
